Thermal unit system



t O r W, nu H .Q @QS )tm QS ON. on: o om 3 Sheets-Sheet l E. V. HILL THERMAL UNIT SYSTEM `Fi1ed April 21, T'1.9152

May 16, i933.

fam. VER/von //LL THERIAL UNI T SYSTEM Filed April 2l, 1932 3 Sheets-Sheet 2 May 16, 1933. E. v. HILL. 1,909,466

THERMAL UNIT SYSTEM Filed April 21, 19:52 3 sheets-sheet s Patented May 16, 1933 i sommes ,EARL vERNoN HILL; or CHICAGO, ILLINOIS i 'DEER-MAI. INIT SYSTEM i Y'Applieation ffiieei i"April 121,

',llhis iinvention mela-tes fto Ia ithermal unit Iair fdistribution system, and :more particu-- flarly, -to :standardized:square :air =distributing f ducts 'associated :with a hoteair for .othe r @f5 lheatingbrf-eoolingapparatus,-or any appafratus for ,conditioning iair, and .to La rectan.- gular uniform unit duct systemewhichdoes not depend upon `artrunk .line system ,of Vin-V stallation'; the speciicffsystem of the present invention comprising thermal. unit ducts ofsucli-crosssection that they have an air vvolume -capacity -of predetermined `ratio to the number fjof thermal units delivered per minute therethrough; other aspects of the invention inc'lude a :rectangularthermal 'unit ,ductrhaving an .air volume capacity equal to the heatingunits;passing through it and directlypropor'tional Lto the .grate .area df the hotair or other .furnace'With 'vvhioihit 'is-used 'and ,proportion al to fthe yamount lof\.heat absobed "bythe a'ir'fin'y a`co.oling,`,system,; a furnace @discharge '.head or any rapparatus for .distiiibutinghot air, cooled air, .or conditioned airV f havingv a l.plurality of; uniform :standard square openings -or outlets iin said discharge. liead to receive uniform ,standard square ducts therein; lfittings `and clamping ,means Afor the square vducts together -With other. consideraf tions, accessory fpar'ts, .and assembling -devices.; all of AWhLich .are 'hereinafter described andclaimed. 4 i

. ."'In .the prior art, hot air rfurnace installations .havelbeen y,provided with either of two typesof distributing systems. One .ofthese is the so-called .trunk line system, tailor. made .for the particular installation, each duct and'branc'h .and .return being especially designed lfor a certain capacity, velocity, and resistance, -the entire system being in dividually constructed(from Working draW- ings, consequentadded .expense to `the home .ofwner A.orbuildien In suc'hxtrunkline systems, 'the airlleaves the furnace. all in one large duct branchesat ,the ,proper 1932'. Serial IN 0.1606273?.

points fto .distribute the :air vvlhere irequired. The othergprior art 'system :is lnown.as -the ,-leader pipesv installation, Where round pipes' are used. These round pipes or leader pipes takev off separately.ffandiindividually from the bonnet of ftheiurnace easing. Such freund pipes occupy a-ilarge amount of head room, do not lend themselves to -compactness in making :turns or connections, and'are unpleasant 'rand unattractive to the eye. v Y 'n The thermal unit system of fthepresent invention replaces both of these prior vant systems. The present finventio'n fobviatessall the disadvantages of -prior froun'dduc't s s'- items, It also =.ov.ereomes :the `additional mstallation cost of trunk line ioveraround ducts, and yet retains 'the advantages `o'fu an individually .designed ftrunl; slinefsystemj; .all at a low cost, togethervvith :thezaddedfiadvantages of saving of :head roomyl simplicity of assembly, standardization of sizesfaand parts :fat the factory, and what is more'important, maximum and proper heat cui4 ingy capacity lvvith higl1esteiiciency,-and it e elimination vof f-guess lWork and speculation on the `part of'the ecraftsman :making the installation.'P 1 f y v II :have -diseoveredthat 'square ythermal unit `ducts fcan be rused and fmaximum teiciency of .-heatgdistribution is :obtainable with -a predetermined velocity4 ofY air ihrough thefduets .in 4accordance With their fheat carryingcapacity and 'that v-such heat carry ing capacity in .B t; fu. per minute should ,be substantially equal `.to the air volume eapaeityinfcubic -feetgper minute and be :directlgr proportional tothefgrate area of the furnace For better understanding of the invention, reference is made fto Ythe accompanying iigures, of which Figure 1 isa chart showing ,the ,relationship-l'have found `existingbetvveen the heat? ing-capacity `oa series .of Ifurnaces of various sizes 1n relation to their gfrateareas; A

Figure 2 is a plan View of the discharge end of a hot air furnace showing square openings or outlets therein for reception of square duct fittings. Y

Figure 3 is a view in elevation of a right angle elbow of square cross-sectional area.

Figure 4 is a view in elevation of a 45 elbow of square cross-sectional area.

Figure 5 vis a plan view of a right angle connection or boot for floor register.

Figure 6 is a front view of the boot shown in Figure 5.

Figure 7 is atop view of a modified form of boot.

Figure 8 is an elevation of the boot shown in Figure 7.

Figure 9 is a plan View of a boot for wall stack connection.

Figure 10 is an elevation of the boot shown in Figure 9.

Figure 11 is a plan view of a modified form of boot for wall stack connection.

Figure 12 is an elevation of the boot shown in Figure 11.

Figure 13 is a plan view of another boot for wall stack connection.

Figure 14 is an elevation of the fitting in Figure 13.

Figure 15 is a plan view of a modified form of the boot for wall stack connection shown in Figure 13.

Figure 16 is an elevation of the fitting of Figure 15. Figure 17 is a view showing the connecting clamp in elevation.

Figure 18 is a plan view of the connecting clamp of Figure 17.

Figure 19 is a View in section of square ducts joined together with the connecting clamp of Figure 17 Figure 20 is an elevation view of a short offset.

Figure 21 is a view in elevation of a long offset.

Referring to Figure 1, it will be seen that the ordinate is the grate area of various hot air furnaces numbered respectively A, B, C, D, and E, while the abscissa is the B. t. u. capacity based upon a furnace efficiency of 60% and a combustion rate of 5 pounds of coal per square foot of grate surface per hour. If Z represents the amount of coal burned in pounds per square foot of grate surface per hour, 7' the B. t. u. value per l pound of the coal, a the grate area in square feet, and ai the furnace efficiency, then K, the furnace capacity in B. t. u. per minute is found from the formula unit and uniform size can be successfully used 1n a hot air furnace home installation if each unit duct delivers one B. t. u. per

Vper cubic foot of air minute for each cubic foot of air carried and discharged through the duct per minute. I have further discovered that a preferred air velocity of 600 feet per minute in a unit duct carrying 200 cubic feet of air per minute satisfies the above conditions, delivers 200 B. t. u. per minute. Knowing the heating capacity of the furnace in B. t. u. from the formula and since the bonnet temperature of the air leaving the furnace is 125o and the return air to the furnace is a difference of 55 Fahrenheit degrees, equivalent to 1 B. t. u.

z gives the maximum Vnumber of ducts from the discharge head of the furnace. A

It will be observed that the heat capacity of the furnace in B. t. u. per minute will be the value identical with the air capacity of the same, and that the number of leader pipes or the number of rooms served can be easily and readily obtained, as shown by the following table:

K=heating Air capacity K Y Furnace no. cgffel? in cu ft. per EO-Oeaverage minute mmute no. of ducts 1v 000 l, 000 v5 1, 25o 1, 250 ey.

A square unit duct carrying 200 cu. ft. of air per minute at a velocity of 600 feet per minute will have a free internal area of lf3 square foot, with dimensions approximateing 7 inches by 7 inches.

A velocity of 600 feet per minute is preferred, but it need not be slavishly followed. For example, a velocity of 1000 feet per minute can be used Without noise'and excessive resistance, but this higher velocity reduces gravity to a negligible amount. I may also go lower and have a velocity of 500 feet per minute, but 600 is best.

Referring to Figure 2 of the drawings, it will be seen that the hot air furnace casing 1 has a number of beveled sides 2 which define the flat top plate 3 having a plurality of square openings l therein at the periphery or margin of the top plate 3. It will be understood that the number of square openings shown are merely illustrative and may be more than 8 openings, the number preferred for furnaces A and B of the grate area of Figure 1; furnaces C and D' of Figure 1 take 1-2 openings, while furnace E takesv 16 openings. However, it will be undestood that the openings in respective fur* naces', while varying in number, are all identical in size and take the same size unitary 'i1-gemmes .discharge openings and discharge ducts are standard and uniform for all size furnaces, and the same size duct and opening is found at the tops of furnaces A and E, although these furnaces vary in capacity.

Installation of the standardized square duct system is preferably made in parallel lines and right angle turns, and only in cases of extreme necessity using anything but a. right turn. Occasionally this will be impossible and the 45 elbow shown in Figure 4 is provided, butthis 45 elbow is used principally in making offsets in the line, as shown in Figures 2.0 and 21. rlwo 45 elbows reversed with a connecting piece of duct gives any offset required. 'Y

In the standard top 3 of the furnace shown in Figure 2, having a standard nulnber of outlets 4, a short run of square duct goes'directly upward to the ceiling elbow and .all ducts are on the same plane below the fioor joists. All runs are preferably parallel or at right angles with the floor joists except in occasional instances where obstructions necessitate offsets, in which case two 45 eibows are joined to obtain the desired offset.

The right angle y'connection or boot for connection to floor registers as shown in Figures 5 and 6 comprises a square end 5 communicating with an enlarged outlet 6 by the angular inclined portion 7. The fittings shown in Figures 7 and 8 are modifications of the fitting of Figure 5 and are intended to make proper connections to other types of fioor registers.

The fittings shown in Figures 9, 10, 11 and 12 are adapted to make connections with wall stacks of rectangular cross-section, as shown in my co-pending application bearing Serial Number 601,635, filed March 28, 1932.

The fittings shown in Figures 13, 14, 15 and 16 are for wall stack connection where the fittings shown in Figures 9 and 12 are inadaptable. It will be observed that the outlet openings 6 in the boots Vof Figures9 to 16 are of comparatively narrow rectangular cross-section, in order that they may correspond to the stack sections running thioughthe house walls, which walls ordinarily are not of a size sufficient to permit the furnace duct to run therethrough. These fittings are square at the inlet 5 to correspond to the furnace discharge line and rectangular at outlet 6 to correspond to the wall stack, with the tapering sides 7 therebetween.

Referring to Figures 17, 18 and 19, a preferred embodiment of my novel clamp means is shown, together with the method in which the square ducts are connected. The clamp proper comprises a relatively inexpensive rectangular stamping having a plurality of apertures therein to receive the screws 9 which have engagement with the iinnerfhindingimenibers 10. V-@ne df `the in- 'rir :binding miembersiis ipreferably :made :of

tthe .ennfiguration shown iinv xFigure 117 Vwith grauer-,eier recessed `portion ll and ya base Yzportien 121m x'order rthatia :pipe seamior lJoint inlay rbelaccommodated. It .willibe observed fthe iinnerhinding amembers l0 are of trapezoidal crosseseetion "with inclined v.sides iltoeexert aggripiorflspring effect .on fthe pipes t'o .sleefcyonneirted vwhen i pressure is ;apipiied .tothe .fmenihers .1.0 ftiirough `the fme- Cdium idf the ibi'nding'screws 19. ein \making thernonnectionishownin)Figure 19, ie'ach end -ofztlre isquane 'duets 1 4 "is shoved vinto the l.rilamp a8 :as far :as'iibwill .1go zand the screws 9 on the four sidestightened,ithereby vdrawing the inner members 10 firmly againstithe iinside :of-theducts,'ibinding them securely -andcmaking` a tight and ir'igid` connection.

' .r iigures :20 .aand 221 .show 'the lpreferred .method of :making :offsets zin'the duct iline. '.lhe member .115 .fof A,Figure :4,1.which1is a45 selbnw :of irentangular nrossesectiom vis used with an intermediate straight member 16 in making a long.offset:as shown in Figure 21, while in making a short offset, the el- :bows zaremier'ely placed :together in reversed .position.

.It will he seen/that #I 1have provideda furmaceV 1er air fconditioning duct system which :requires :merely ia ypair lof .lsnips =.to"cutfthe .standard rpipes .fto `proper .length fand .a wrench for tightening the connecting clamps. Not only are the ducts standardk.ized.size, ibut velocity inthe ducts .as well .as .their heat-carryingcapacity isz standardized so .that calculations .are simplified vfor installing .heating .and/or -cooli-ng systems. :In mechanical .refrigeration systems Afor homes, temperature drop .of .from '77.5 to 50 in the washer .wilLgivea-cooling capac- .of.onefhalf-.themeatingcapacity and each .standardduct wilLhave 100.13. t.-u.'of coolnsapaeitv. n *"It :will .be .seen .thatmyrsquare duct ther- :mal .unit .system can xbe .used :in home :air heating and-coolingsystems withadvantage,

las .fan .circulation ,particularly permits zthe ,prqpeixamountof .heat andthe 'properfquantity .,o`fair .to Aflow through :the duct for `a room of average size. .llhe:fittings,1as 'hereindescribed,.arefof immense advantage over the .trunk `line fittings-of the prior art, :not

.onlyinsimplicityof construction andzinstal- Jantien, Y.but-in .adaptability also. .For example, the elbows of squarecress-section-can:be turned .in various directions. Cold .air =re turn lines should preferably be omitted, but iusedgmay lie-fabricated to the size required depending upon the size of the cold air registers. Dampers, or preferably adjusting registers, may be used in balancing and adjusting the system. A damper may be used in each unit duct'in the basement, if desired.

iami

aio

It Will be understood that my thermal unit system is applicable to the installation of air conditioning equipment on steam and hot Water jobs as Well as on Warm air furnaces.

@g5 When my thermal unit system is used With an air conditioner in conjunction With a hot Water heating plant, the conditioning apparatus is placed in the basement adjacent the hot Water boiler, and thermal unit SPO ducts are vertically disposed upwardly from the air conditioner. The top of the air conditioner is provided With a discharge end having square openings or outlets therein for reception of square duct fittings, sim- ',g ilar to the discharge end of the Warm air furnace shown in Figure 2.

I claim:

l. A Warm air furnace having atop With a plurality of uniform square shaped opena2@ ings therein, and uniform distributing ducts in said openings of corresponding shape, said furnace ygenerating an amount of heat per minute as determined from the formula ma L25 K 60 in Which Z is the coal burned in pounds per square foot of grate surface per hour, 1 is the B. t. u. value of the coal, a is the grate *50 area ofthe furnace in square feet, and a: is the furnace efliciency, the maximum number of saidKducts being determined by the formula 200 2. In a Warm air furnace, a top having a plurality of square openings of uniform size on said top and adapted to receive vertical square ducts therein, said openings being located about the marginal edge of said top and arranged to permit the ducts to be separated from one another.

3. A standard Warm air furnace installation comprising a furnace, a top therefor having a plurality of square openings adjacent the margin thereof, and a plurality of ducts of square crosssection fitting in said openings, all of said ducts being of uniform size'and each of said ducts having a capacity of carrying one B. t. u. per minute per cubic foot of air passing therethrough at a velocity of 600 feet per minute.

4. A top for a Warm air furnace having a square horizontal portion, and square openings in the horizontal portion adjacent to and having their sides parallel to the edges of said horizontal portion.

In testimony whereof I hereunto set my hand.

EARL VERNON I-IILL. 

